Method of agglomerating pulverulent materials



Patented Jan. 17, 1928.

UNITED STATES PATENT OFFICE.

HERMANN SIGISMUND SGHULTZE, F GRTESHEIM-ON-THE-MAIN, GERMANY, AS-SJEGNOR TO THE FIRM I. G. FARBENINDUSTBIE AKTIENGESELLSCHAFT, OF FRANK-FURT-ON-THE-MAIN, GERMANY.

METHOD OF AGGLOMERATING PULVERULENT MATERIALS.

No Drawing. Application filed May 5, 1927, Serial No. 189,165, and. inflermany April 10, 19%.

This invention relates to a method of transforming pulverulent materialsinto small pieces adapted for use in gas reactions.

When material present in the form of powder, is to react in greatquantities, simultaneously and uniformly with gases, a difficulty arisesdue to the fact, that the gases, when passed through the powder, meetwith an excessive resistance. Various methods have been roposed toovercome this diihculty, but all 0? them are subject to peculiardrawbacks. When operating on a large scale, recourse has been taken tobriquetting and agglomeration. With the latter method, however, theresulting agglomerates, for instance balls, are of so different a sizethat difierent lengths of time are required for completing the reactionin the interior of the agglomerates whereby the whole duration of thereaction is undersirably prolonged.

According to the method forming the object of the present invention, thematerial under treatment is obtained, independently of its nature, inthe form of highly porous, small pieces having a surprisingly uniformsize, viz, in the form of small balls, of approximately the size ofpeas.

For carrying out my invention, the finely powdered material to betransformed topeas is spread in a uniform layer ofabout one half to oneinch, preferably upon a conveyer belt, whereupon the latter is passedbeneath a series of dropping pipes from which drops of a suitableliquid,for instance, water, or a salt solution, are made to drop.

The distance between the adjacent drops is calculated so as to preventthe uniting of the drops. By absorbing the liquid the powder is formedito ball-like, moist bodies or peas of a oosely coherent mass, whichbodies may be easily separated from the excess of powder by carefulsifting-0E. The sifted, still moist peas are preferably left upon thesieve and dried in any suitable manner, for instance, by passing thesieve, forming a conveyer belt, through a drying- Mln. The moisture ofthe peas amounts to about 10 to 15%; the amount de ending upon thenature and the fineness of t e powdered material. A preliminarycondition for the formation of the.peas is that the material undertreatment be capable of being wetted.

The mechanic stability of the dried peas entirely depends upon thenature of the powder employed and the additions made to the liquid,which additions must be ascertained from case to case by experiment.Salts or mixtures of insoluble substances with a salt, require, as arule, only a treatment with pure water. As the size of drops may bevaried in rather wide limits by varying the form of thedropping-surfaces, I am'able to produce peas of greater or smallerdiameter, as desired.

The charge of a reaction chamber filled with dried peas opposes only asmall resistanceto the passage of gases, although the reactivesurface-is a considerable one. Owing to the small diameter of the singlepeas and the great porosity of the material, the reaction penetratesrapidly and uniformly to the interior of the peas. The hardness of thedried peas enerally suflices for allowing of piling up it crimes to aheight of several meters. I

Owing to its simplicity the method according to my present inventionfisadapted to be advantageously substituted in many cases for the hitherto1 prevailing, troublesome method of ressing pills, or, generallyspeaking, to ena le reactions between gases and pulverulent materials ona factorial scale.

I claim 1. The method of'transforming pulverulent material into smallpieces of uniform size adapted for use in gas reactions which consistsin spreadin the material in the form of a layer, ma ing drops of aliquid fall separately upon the said layer, separating the resultingball-like bodies from the excess of powder, and drying the said bodies.

2. Method in accordance with claim 1, comprising sifting 01f theresulting ball-like bodies and conveyin the sieve with the balllikebodies thereon t rough a drying-kiln.

In testimony whereof I aflix my signature.

HERMANN S. SCHULTZE.

